President Trump should enhance military cooperation with Taiwan as part of an effort to counter Chinese aggression in the Asia-Pacific, according to a newly unveiled proposal from four senators.

Sen. Cory Gardner, R-Colo., wants Trump to authorize “regular arms sales to Taiwan” and expand the U.S. Navy’s presence in the region, where China has made a series of aggressive assertions of sovereignty over key shipping lanes. Those security proposals contribute to one plank of a broader package known as the Asia Reassurance Initiative Act, which lawmakers hope will guide the administration in maintaining the U.S. alliance system around a rising China.